A clinical and electrophysiological evaluation of myoclonus.
The records of 23 consecutive patients with myoclonus who were seen during a 16-month period were analyzed prospectively. The patients were divided into two groups: epileptic and nonepileptic. The epileptic patients had focal and stimulus-elicitable myoclonus with enlarged somatosensory evoked potentials and enhanced long-loop reflexes, and they responded well to anticonvulsants, especially clonazepam and valproic acid. The nonepileptic group had massive and spontaneous jerks with normal-sized somatosensory evoked potentials and long-loop reflexes, and they responded poorly to anticonvulsants. Evaluation of these clinical and electrophysiologic characteristics can help in the classification of obscure movement disorders and in predicting responses to therapy.
D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000627:therapeutic use; D004569:Electroencephalography; D004594:Electrophysiology; D004831:Epilepsies, Myoclonic / Q000188:drug therapy / Q000503:physiopathology; D005071:Evoked Potentials; D005260:Female; D006801:Humans; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D009207:Myoclonus / Q000503:physiopathology*; D009431:Neural Conduction; D010543:Peroneal Nerve / Q000503:physiopathology; D012018:Reflex
D000927:Anticonvulsants